Welding on an Aluminum Harley head

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Hello all,I got hit up a few hours ago with a project involving repairing an motorcycle head that has stripped out exhaust manifold stud holes.  I have done a few of these and always the head is brought to me and I do it on my work bench.The client asked me to do it while still assembled to the engine.  I am up to the challenge but will not use TIG as I normally would as the situation is not conducive to positioning the part for ease of welding and control (flat).What I thought of was using Aladdin 3 in 1 aluminum brazing rod to fill the holes with molten rod (it melts about 400 degrees before aluminum does) and dipping the new stud into the hole thus having the molten metal cool around the stud forming new threads in the process. My thinking was to have him lay the cycle down so that the exhaust ports are facing up so gravity can help me with the molten metal flowing into the holes.This procedure was shown on a web site of one of these types of products (there are various such rods on the market) and the tech did just as I had described.  The advantage to this is that the hole is not gouged out and filled as I  have done in the past but simply filled in like soldering.  The problem I see is that it means heating the head to above 600 degrees so that this material will flow.  It runs just like solder once it gets to temperature.  Can damage result to the engine in attempting this type of repair?  could I burn out the head gasket in the process for example?Excuse me for sounding simple with these questions but I really want to know what you think.  Is this type of repair doable?  Or should I tell the client to take the head off and let me do it on the bench?  Apparently this is his only transportation to work and needs it done by Monday so he can get to his job.For those of you who have not tried this stuff, I will tell you that it works great.  It enable me to perform a repair weld on a pot metal part for a tire shop they needed to stay up.  Anyone that has attempted weld repairs on pot metal knows that using traditional methods it is all but impossible to do.Thanks and I await your thoughts,TonyLast edited by therrera; 04-24-2011 at 02:37 AM.Reason: to add more detail.
Reply:Heli-coilMiller Syncrowave 350Millermatic 252/ 30A spoolgunMiller Bobcat 225g w/ 3545 spoolgunLincoln PowerArc4000Lincoln 175 Mig  Lincoln 135 Mig Everlast 250EX TigCentury ac/dc 230 amp stickVictor O/AHypertherm 1000 plasma
Reply:Sorry, I forgot to mention.  The reason I was called is because the Heli-coil attempt failed and the hole is way too big now.  I don't know the details, just that he tried that and it is now worse.Tony
Reply:i second the helicoil, i would not consider welding on a head that small in place.Dynasty 200DXPassport plus w/ spoolmate 100victor 315c oxy/(act and prop)Miller digital elitemilwaukee power tools
Reply:o, that is unfortunateDynasty 200DXPassport plus w/ spoolmate 100victor 315c oxy/(act and prop)Miller digital elitemilwaukee power tools
Reply:Tell him to pull the dang head off... there aren't even timing chains to deal with...
Reply:You can pull the head while engine is still in the frame, It will be easier and a better job.Why risk it?Tim Beeker.
Reply:Stepped stud (larger on one end) even if a larger Heli-Coil has to be used.  McMaster-Carr sells them as well as many well stocked hardware stores.MM200 w/Spoolmatic 1Syncrowave 180SDBobcat 225G Plus - LP/NGMUTT Suitcase WirefeederWC-1S/Spoolmatic 1HF-251D-1PakMaster 100XL '68 Red Face Code #6633 projectStar Jet 21-110Save Second Base!
Reply:Second - the stepped stud .
Reply:Or a steel insert... just made one the other day... fubar'd threads resulted in a steel insert OD threads were 1/2" ID threads were 5/16"...
Reply:Originally Posted by kustomizingkidOr a steel insert... just made one the other day... fubar'd threads resulted in a steel insert OD threads were 1/2" ID threads were 5/16"...
Reply:Hole too big for heli-coil. use big sert or similar (larger od than heliciol). Hole too big for that? Drill, tap, install solid type pipe plug, then drill and tap whatever size you need. Low temp solder- like stuff won't work.PeterEquipment:2  old paws2  eyes (that don't look so good)1  bad back
Reply:Originally Posted by castweld . . . Hole too big for that? Drill, tap, install solid type pipe plug, then drill and tap whatever size you need. Peter
Reply:Thank you all for your input.  As usual it is a learning experience.  The fact that all of you don't recommend such a fix as I described was good in itself, but the deciding vote was the comment of the operating temperature of the head where the possibility of the Aladdin stuff not holding did the trick.Plus I was concerned with the possibility that in getting it up to the right temperature (about 700 degrees or so), I could ruin the head gasket if they are anything like automobile gaskets with composite materials.I once welded on an aluminum truck head right near where it met the head gasket and created a tiny pinhole coolant leak.  Luckily a little radiator stop leak applied liberally, stopped it and it has been running fine so far to date.I will cancel the service call and suggest that he take the head off.Thanks,Tony
Reply:Originally Posted by duaneb55Stepped stud (larger on one end) even if a larger Heli-Coil has to be used.  McMaster-Carr sells them as well as many well stocked hardware stores.
Reply:What year is the Harley? You may not have enough material to go oversized. Welding may be only option.Tim Beeker.
Reply:I have done a bunch of those when I had my after market Harley shop.....Believe me when I tell you this.......The only way to do a really GOOD  job is to remove the head.....Anything else will be a crap job...die grind the side of the hole down to the bottom and fill it in with 4043 filler......drill and install a heli-coil because the metal will be too soft to support regular threading process....Then use a stud.....Do it this way or you will be hating life.....Been there done that.....  Miller Dynasty 350Twenty Six HammersThree Crow BarsBig Rock
Reply:This should work twincertshttp://www.helicoil.com.sg/HeliCoil-...-Twinserts.htmVinnie
Reply:Only problem with this fix is there isn't enough room outside the original hole to drill larger, has to be tig weld repaired  Miller Dynasty 350Twenty Six HammersThree Crow BarsBig Rock
Reply:Well everybody,The final word is that this job was canceled.  I had a 1pm appointment to attempt the repair in position as I had written about at the start.  I called the client to let him know that I could not guarantee that there might not be secondary damage or problem as a result of doing it while attached to the block.  I was thinking mainly of possible damage to the head gasket and that because I would need to heat up the area to 700 degrees it may have some unwanted side effects.  I was confident in using this material for the repair as described (filling the hole with molten rod and letting the new stud form new threads upon cooling).  I was uncertain about applying that much heat around the area and how other parts may get damaged (gaskets, o-rings, plastic clips or retainers, paint scorched, etc.).He replied that he understood and was willing to accept the risk.  I had to make it clear that if I attempted the repair in this fashion and other damage was caused, he would still be liable for my bill for showing up and doing the work.  So the job was still on.Then he called me about 10 minutes later to say that he felt uncomfortable with my hesitation and that would consult with other welders in the area to get other opinions.  He called off the job.Personally, I was looking forward to the repair just for the experience.  Just like I do many aluminum repairs in position for auto repair and body shops, knowing this can be done will be a good tool to have when a similar situation presents itself.  I had already told him that if I could not get the studs to take, I would only charge him gas money, $10.I had already let him know that I had not done a repair like that in position.I appreciate your thoughts on the subject and now I know that there are a variety of ways to fix this type of damage (heli-coil, double-heli-coil, stepped stud, etc.) besides taking a TIG torch to it.  Thanks for the links to the product in question.Tony
Reply:Good call advising pulling the heads.600 degrees is a LOT warmer than ordinary Harley operating temperature. I'd venture you'd crisp the valve stem seals, upper pushrod tube seals, and maybe rocker shaft seals on a Shovel head. Head gaskets themselves are tough, and if it's a solid copper one it should be fine.If it was my bike the heads would be off. You can do Harleys by the roadside in a pinch. It's not a Hondapottamus flat six.
Reply:Originally Posted by B_CI have done a bunch of those when I had my after market Harley shop.....Believe me when I tell you this.......The only way to do a really GOOD  job is to remove the head.....Anything else will be a crap job...die grind the side of the hole down to the bottom and fill it in with 4043 filler......drill and install a heli-coil because the metal will be too soft to support regular threading process....Then use a stud.....Do it this way or you will be hating life.....Been there done that.....
Reply:Hi DougAustinTX,I've done some of these as well in this fashion (except for the heli-coil after welding).  What he wrote was to die grind the side of the hole down so that you basically have a rounded groove that you can fill in.  What I use is a side grinder with a worn down disc (smaller diameter) and I gouged out the side of the hole leaving an open channel that I fill in with 4043.Tony
Reply:Listen to B_C, his way is the best way...-at the job-Miller Dynasty 200DXMiller Syncrowave 350MillerMatic 250Millermatic 350Miller Bobcat 250Lincoln AC225Miller Spectrum 625 Plasma-at home-Everlast PP256Longevity WeldAll 256PI'slow is smooth, smooth is fast'
Reply:Originally Posted by DougAustinTXBC:  For my own edification, could you explain how you "fill the hole" with 4043?  My inclination would be to "plug" the hole with a new metal plug, weld the plug, then drill and tap.  How do you manage to get the 4043 into the hole and welded solid?Tony--heating aluminum castings above 600 degrees takes them into the plastic range,on an assembled, torqued head--guarantee to ruin that head...or any other casting,Over 400 degrees F with AL castings and you're courting problems.Localized heating/welding on casting assemblies with pressed in things, over 200 degrees F,can see stuff coming loose and dropping out....unless it's done in controlled conditions, uniform heat, controlled cool down, withfixtures to maintain casting dimensions. (On F-111 engine parts, precision, 0 porosity,x-rayed, investment castings I had made--this was done, to gently size the castings...and wasdone by pros that did this for a living. I did finish machining after.)Blackbird
Reply:Hi Dave and all,I let this job go and will keep this information in mind when working with these kinds of parts.  I am called on frequently to weld on aluminum castings in the form of transmission cases or oil pans, motorcycle parts, etc.My procedure is basically to pre-heat the part all over and focus on the area to be welded to burn out any oil, grease, etc. and begin welding in small steps.  The last casting I did was on a hard to get transmission that had a broken out filler hole.  I welded an aluminum compression fitting to it as a work around to filling the plug hole and then drilling and tapping it out for the original drain plug.I welded it in little steps like I would do for cast iron and not let the part get too hot.  I would do about a 1/2" to 3/4" inch at a time and let it cool down.  I would let it cool until I could barely keep my bare hand on it.It seemed to work alright, just took time to finish.Thanks,Tony
Reply:Refering to the original question about heat, in my opinion, 700 degrees would present zero problems on the exhaust side of the head.  I have very little experience on Harley's but I have had pyrometers on all my diesels, most of my snowmobiles and several bikes, not one of them runs under 700 degrees under throttle, a couple of my cummins engines, with the pyro installed before the turbo, will hit 1400 VERY easily.  A bone stock 2005 CR Cummins engine will hit 1450 every time you hit the throttle, and run continuously over 1000 degrees, I know, I have 2 of them with pyrometers.  So I do not think 700 degrees would present a problem.6 Miller Big Blue 600 Air Paks2 Miller 400D6 Lincoln LN-25's4 Miller Xtreme 12VS2 Miller Dimension 812 4 Climax BW-3000Z bore welders Hypertherm 65 and 85Bug-O Track BugPair of Welpers
Reply:Originally Posted by therreraHi Dave and all,I let this job go and will keep this information in mind when working with these kinds of parts.  I am called on frequently to weld on aluminum castings in the form of transmission cases or oil pans, motorcycle parts, etc.Thanks,Tony
Reply:I'd take BC's advice to the bank.  Not like it's his "first rodeo" when dealing with a Harley.Some "other posters" must have had a different experience when dealing with the Aladin Alum rods.  With the exception of "pot metal" repairs, the only thing I've found them useful for is making a proper tig repair very difficult (cleaning the crap out) if not impossible.Syncro 250 DX Dynasty 200 DXMM 251 w/30A SG XMT 304 w/714 Feeder & Optima PulserHH187Dialarc 250 AC/DCHypertherm PM 1250Smith, Harris, Victor O/ASmith and Thermco Gas MixersAccess to a full fab shop with CNC Plasma, Water Jet, etc.
Reply:Originally Posted by castweldHole too big for heli-coil. use big sert or similar (larger od than heliciol). Hole too big for that? Drill, tap, install solid type pipe plug, then drill and tap whatever size you need. Low temp solder- like stuff won't work.Peter
Reply:Originally Posted by ExpatWelderRefering to the original question about heat, in my opinion, 700 degrees would present zero problems on the exhaust side of the head.  I have very little experience on Harley's but I have had pyrometers on all my diesels, most of my snowmobiles and several bikes, not one of them runs under 700 degrees under throttle, a couple of my cummins engines, with the pyro installed before the turbo, will hit 1400 VERY easily.  A bone stock 2005 CR Cummins engine will hit 1450 every time you hit the throttle, and run continuously over 1000 degrees, I know, I have 2 of them with pyrometers.  So I do not think 700 degrees would present a problem.
Reply:Originally Posted by dave powelsonOP was musing about pre-heating the ENTIRE casting to 700˚F +....that's disaster.You're describing localized heat measurements--different animal.
Reply:Originally Posted by DougAustinTXBC:  For my own edification, could you explain how you "fill the hole" with 4043?  My inclination would be to "plug" the hole with a new metal plug, weld the plug, then drill and tap.  How do you manage to get the 4043 into the hole and welded solid?